Agrochemical compositions for reducing agrochemical residues

ABSTRACT

An agrochemical composition containing dicamba or its salt, a sulfonamide herbicide free acid and a solid base. A method of controlling field weeds with the use of the composition. A method of reducing and/or removing agrochemical composition residues in an application tank, as well as a method of preparing an agrochemical composition, including the mixing of a solid base with dicamba or its salt and a sulfonamide herbicide free acid.

This application is a 371 national phase entry of PCT/CN2013/074758,filed 26 Apr. 2013, which claims benefit of CN 201210130353.4, filed 27Apr. 2012, the entire contents of which are incorporated herein byreference for all purposes.

BACKGROUND

Technical Field

The present disclosure relates to an agrochemical composition comprisingdicamba or its salt, a sulfonamide herbicide free acid and a solid base.The present disclosure also relates to a method of controlling fieldweeds with the use of the said composition. Furthermore, the presentdisclosure relates to a method of reducing and/or removing agrochemicalcomposition residues in an application tank, as well as a method ofpreparing an agrochemical composition, comprising the mixing of a solidbase with dicamba or its salt and a sulfonamide herbicide free acid.

Description of Related Art

Sulfonamide herbicides are a class of compounds of high herbicidalactivity with sulfonylurea or triazolopyrimidine as core structure.Compared with other conventional herbicides, sulfonamide herbicides showsignificantly higher herbicidal activity. However, the cost ofsulfonamide herbicides is relatively high. In addition, the effect ofsulfonamide herbicides on controlling monocotyledonous weeds is betterthan that on dicotyledonous weeds. Therefore, agrochemical compositionscomprising the combined use of a sulfonamide herbicide and otherherbicides are known in the art.

The combined use of a sulfonamide herbicide and dicamba or its saltexhibits significant synergism with better controlling effect onmonocotyledonous and dicotyledonous weeds. It broadens the herbicidalspectrum, lowers the cost and shortens the farming time. Moreover,application in multiple amount of normal field usage is not only safe tothe growing crops, but also safe to the succeeding crops thereafter.CN1169441 discloses an herbicidal formulation for controlling weeds incorn fields, which comprises a mixture of dicamba or its salt andnicosulfuron. The examples disclose a wettable powder of 1% dicamba+6%nicosulfuron; an aqueous suspension of 5% dicamba+1% nicosulfuron; anemulsion concentrate of 9% dicamba+1% nicosulfuron; and an aqueoussolution of 39% dicamba+1% nicosulfuron. CN1433688 discloses anherbicidal formulation for controlling weeds, which comprises a mixtureof dicamba or its salt and tribenuron-methyl. The examples disclose awettable powder of 40% dicamba+4% tribenuron-methyl; a dry flowable of48% dicamba+2% tribenuron-methyl; and a wettable powder of 49%dicamba+1% tribenuron-methyl. CN102365967 discloses an herbicidalcomposition for wheat fields, which comprises mesosulfuron-methyl anddicamba. The examples disclose a wettable powder of 19.5% dicamba+1%mesosulfuron-methyl; a wettable powder of 29.2% dicamba+1.5%mesosulfuron-methyl; a wettable powder of 39.2% dicamba+1.8%mesosulfuron-methyl; a water-dispersible granule of 34.3% dicamba+1.5%mesosulfuron-methyl; a suspension of 58.3% dicamba+3%mesosulfuron-methyl; and an emulsion concentrate of 50.8% dicamba+1.8%mesosulfuron-methyl. Sulfonamide herbicides are a class of highly activepesticides. Therefore, it is necessary to remove all sulfonamideresidues carefully from the spray equipment (spray tank) used forapplying pesticides on crops before using it to treat crops sensitive tosulfonamide or that would be damaged by sulfonamide used in the previousapplication. Adequate cleanout may require a rinsing procedure that istime-consuming and results in wastewater disposal problem. In theexamples of CN1169441, the herbicidal mixtures of dicamba andnicosulfuron, formulated as emulsion concentrates, aqueous solutions,aqueous suspensions and wettable powders, have an amount of 1%-6%nicosulfuron. In the examples of CN1433688, the herbicidal mixtures ofdicamba and tribenuron-methyl, formulated as wettable powders and dryflowables, have an amount of 1%-4% tribenuron-methyl. In the examples ofCN102365967, the herbicidal mixtures of dicamba and mesosulfuron-methyl,formulated as wettable powders, water-dispersible granules, suspensionsand emulsion concentrates, have an amount of 1%-3% mesosulfuron-methyl.In the abovementioned herbicidal mixtures of dicamba and sulfonamide,the amount of sulfonamides is relatively low, ranging from 1% to 6%.Since the amount of sulfonamides is low, there may not be any residueremaining in the spray tank or the amount of residue remaining islimited. However, a further increase in the amount of sulfonamides inthe mixture of dicamba and sulfonamides inevitably results insulfonamide residues remaining in the spray tank. Large quantity ofwater is required to wash the spray tank in order to reduce the amountof insoluble contaminative sulfonamide residues.

SUMMARY

In view of the above shortcomings, the present invention, in anembodiment, provides an agrochemical composition for controlling fieldweeds, which comprises dicamba or its salt, a sulfonamide herbicide freeacid and a solid base. The agrochemical composition according to thepresent invention can be in solid form, for example, in the form ofwettable powder or water-soluble granule, preferably in the form ofwater-soluble granule (SG).

In the first aspect, the present invention provides an agrochemicalcomposition for controlling field weeds, which comprises dicamba or itssalt, a sulfonamide herbicide free acid and a solid base, and optionallyany agriculturally acceptable carriers. At least one of the followingingredients may be added to the said agrochemical composition asrequired: wetting agents, dispersing agents and diluents.

In an embodiment, the said agrochemical composition is in solid form.Preferably, the said agrochemical composition is in the form of wettablepowder (WP), water-soluble powder (SP) or water-soluble granule (SG),more preferably in the form of water-soluble granule.

Under normal conditions, the agrochemical composition according to thepresent invention is ultimately applied in liquid form (e.g. solution,emulsion, or suspension). Therefore, the present invention also includesthese liquid agrochemical compositions.

In another embodiment, the said solid base is selected from sodiumhydrogen carbonate, sodium carbonate, disodium hydrogen phosphate,sodium phosphate, potassium carbonate, dipotassium hydrogen phosphate,potassium phosphate, potassium hydrogen carbonate, potassium hydroxide,sodium carbonate hydrate, sodium acetate, sodium tripolyphosphate,sodium phosphate dodecahydrate, diammonium hydrogen phosphate, sodiumsilicate, sodium trisilicate, sodium polyphosphate, sodium, potassiumpyrophosphate, and any combination thereof.

In another embodiment, the said sulfonamide herbicide free acid isselected from nicosulfuron, tribenuron, metsulfuron, bensulfuron,penoxsulam, rimsulfuron, sulfometuron, thifensulfuon, mesosulfuron,pyrazosulfuron, chlorsulfuron, tritosulfuron, azimsulfuron,amidosulfuron, ethametsulfuron, chlorimuron, diclosulam, florasulam,flumetsulam, metosulam, and any combination thereof.

In another embodiment, the weight ratio of the said solid base to thesulfonamide herbicide free acid in the said agrochemical composition isfrom 1:90 to 90:1; the said solid base is present in an amount of atleast 1% of the total weight of the agrochemical composition.

In the second aspect, the present invention provides a method ofcontrolling field weeds, which comprises the application of theagrochemical composition mentioned in the first aspect of the presentinvention.

In the third aspect, the present invention provides a method of reducingand/or removing residues of the agrochemical composition comprisingdicamba or its salt and a sulfonamide herbicide free acid in anapplication tank (e.g. spray tank). The method comprises providing theagrochemical composition mentioned in the first aspect of the presentinvention and applying the said agrochemical composition with anapplication tank (e.g. spray tank).

In the fourth aspect, the present invention provides a method ofpreparing an agrochemical composition which comprises the mixing of asolid base with dicamba or its salt and a sulfonamide herbicide freeacid. For example, to prepare the agrochemical composition mentioned inthe first aspect above through the said method.

In the fifth aspect, the present invention also provides a solid basefor the use of reducing agrochemical composition residues in anapplication tank. The said agrochemical composition comprises dicamba orits salt and a sulfonamide herbicide free acid.

Compared to similar agrochemical compositions in the art, theagrochemical composition of the present invention, comprising a solidbase, dicamba or its salt, and a sulfonamide herbicide free acid, cansignificantly reduce the residues of herbicidal active ingredients in anapplication tank (e.g. spray tank). Thus the said application tank doesnot require complicated and time-consuming treatment before using it forsubsequent application of other agrochemical substances. This lowers oreradicates the adverse effect on the target of subsequent application.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Sulfonamide herbicides are a class of compounds of high herbicidalactivity with sulfonylurea or triazolopyrimidine ascore structure.Suitable examples of sulfonamide herbicides include but not limited tonicosulfuron, tribenuron, metsulfuron, bensulfuron, penoxsulam,rimsulfuron, sulfometuron, thifensulfuon, mesosulfuron, pyrazosulfuron,chlorsulfuron, tritosulfuron, azimsulfuron, amidosulfuron,ethametsulfuron, chlorimuron, diclosulam, florasulam, flumetsulam andmetosulam.

Compared with other conventional herbicides, sulfonamide herbicides havea significantly high herbicidal activity. However, the cost ofsulfonamide herbicides is relatively high. In addition, the effect of asulfonamide herbicide on controlling monocotyledonous weeds is betterthan that on dicotyledonous weeds. Therefore, agrochemical compositionscomprising the combined use of a sulfonamide herbicide and otherherbicides are known in the art.

It is desirable to clean out the spray equipment before the equipment issubsequently used to treat crops which are sensitive to the sulfonamideherbicide used in the previous application. Adequate cleanout mayrequire a rinsing procedure that is time-consuming and results inwastewater disposal problem. Furthermore, cleanout can be affected ifthe spray equipment contains organic deposits remaining from previouscrop protection chemical applications or from other chemicals tank-mixedwith the sulfonamide herbicide. In respect of the abovementionedherbicidal mixtures of dicamba and sulfonamide, the problem of difficultspray tank cleanout is exacerbated by the increased amount ofsulfonamide in the mixture of dicamba or its salt and sulfonamide. Thisis because the tank mixes of the mixture of dicamba or its salt andsulfonamide are primarily suspensions or emulsions. Suspendedsulfonamide particles can accumulate on tank walls, in tubing, or beretained by organic deposits that may be present inside the tank. If alater tank mix transfers sulfonamide into solution or suspension,sensitive crops can be damaged.

This problem can be avoided by adding a solid base into the compositioncomprising dicamba or its salt and a sulfonamide free acid. Therefore,under general usage, only a few or even no sulfonamide particlesaccumulating on the interior surface of the tank or embedding in theorganic deposit which may be formed on the surface.

Therefore, the present invention, in an embodiment, provides anagrochemical composition for controlling field weeds, which comprises atleast one sulfonamide free acid herbicidal active ingredient, dicamba orits salt, and at least one solid base, optionally with at least one ofthe following ingredients as required: wetting agents, dispersing agentsand diluents.

The said solid bases include those having cations derived from alkalimetals or ammonium, and counterions selected from carbonate, phosphate,oxide, hydroxide, acetate and silicate anions, including dimeric,trimeric and polymeric forms thereof such as pyrophosphate,tripolyphosphate, polyphosphate and trisilicate, etc. Examples of solidbases include but not limited to the anhydrous and hydrated forms ofsodium acetate (NaOAc), sodium phosphate (Na₃PO₄), disodium hydrogenphosphate (Na₂HPO₄), potassium phosphate (K₃PO₄), dipotassium hydrogenphosphate (K₂HPO₄), diammonium hydrogen phosphate ((NH₄)₂HPO₄), sodiumcarbonate (Na₂CO₃), sodium hydrogen carbonate (NaHCO₃), potassiumcarbonate (K₂CO₃), potassium hydrogen carbonate (KHCO₃), lithium oxide(Li₂O), lithium hydroxide (LiOH), lithium carbonate (Li₂CO₃), sodiumhydroxide (NaOH), lithium phosphate (Li₃PO₄), lithium silicate(Li₂SiO₃), lithium orthosilicate (Li₄SiO₄), potassium hydroxide (KOH),sodium silicate (Na₂SiO₃), sodium orthosilicate (Na₄SiO₄), potassiumpyrophosphate (K₄P₂O₇), sodium trimetaphosphate ((NaPO₃)₃), sodiumhexametaphosphate ((NaPO₃)₆), sodium polyphosphate ((NaPO₃)_(n)), sodiumpyrophosphate (Na₄P₂O₇), sodium tripolyphosphate (Na₅P₃O₁₀) and sodiumtrisilicate (Na₂Si₃O₇).

It has been surprisingly found that bases containing cations of alkalimetals like sodium or potassium have excellent performance in theexamples of the present invention. Therefore, it is preferable to choosebases containing cations of alkali metals like sodium (Na⁺) andpotassium (K⁺), more preferably sodium. In addition, in consideration ofcost, efficiency and convenience etc., it is more preferable to choosebases containing counterions selected from acetate (OAc⁻), hydrogencarbonate (HCO₃ ⁻), carbonate (CO₃ ²⁻), hydrogen phosphate (HPO₄ ²⁻) andphosphate (PO₄ ³⁻). According to the result of the examples of thepresent invention, the inventor has also found that solid bases in theforms of carbonates and phosphates demonstrate excellent performance.Thus, carbonates and phosphates are more preferable. Preferred basesinclude sodium acetate, sodium carbonate, disodium hydrogen phosphate,sodium phosphate, potassium hydrogen carbonate, potassium carbonate,dipotassium hydrogen phosphate and potassium phosphate. Theabovementioned bases include hydrated forms thereof, such as sodiumcarbonate monohydrate, disodium hydrogen phosphate hexahydrate, sodiumphosphate dodecahydrate, potassium carbonate sesquihydrate, dipotassiumhydrogen phosphate trihydrate and potassium phosphate octahydrate.According to the efficacy data from the abovementioned examples, morepreferred are sodium carbonate, sodium phosphate, potassium carbonateand potassium phosphate, including hydrated forms thereof. The mostpreferable base is sodium carbonate, including hydrated forms thereof.

Addition of sufficient amount of a solid base into a compositioncomprising a sulfonamide free acid active ingredient and dicamba or itssalt can enhance the solubility of the sulfonamide free acid activeingredient in water, resulting in a clear aqueous spray of herbicidalmixture comprising a sulfonamide free acid and dicamba, which in turnleads to a decrease in the amount of sulfonamide residues in the spraytank. The amount of the solid base required is based on theconcentration of the sulfonamide free acid active ingredient. The weightratio of the solid base to the sulfonamide free acid active ingredientis from 1:90 to 90:1. The solid base is present in an amount of at least1% of the total weight of the agrochemical composition comprising thesulfonamide free acid active ingredient.

Wetting agents in the agrochemical composition of the present inventioninclude but not limited to sodium alkyl sulfosuccinate, laurates, alkylsulfate and phosphate esters, acetylenic diols, ethoxyfluorinatedalcohols, ethoxylated silicones, alkyl phenol ethoxylates, benzenesulfonates, alkyl-substituted benzene sulfonates, alkyl á-olefinsulfonates, naphthalene sulfonates, alkyl-substituted naphthalenesulfonates, condensates of naphthalene sulfonates and alkyl-substitutednaphthalene sulfonates with formaldehyde, and alcohol ethoxylates. Ofnote are compositions comprising up to 10% by weight on a water-freebasis of the wetting agent.

Dispersing agents include but not limited to sodium, calcium andammonium salts of lignosulfonic acid (optionally polyethoxylated);sodium and ammonium salts of maleic anhydride copolymers; sodium saltsof condensed phenolsulfonic acid; and naphthalene sulfonate-formaldehydecondensates. Of note are compositions comprising up to 10% by weight ona water-free basis of the dispersing agent. Sodium lignosulfonate isparticularly useful for the method and composition of the presentinvention.

Diluents may be water-soluble or -insoluble. Soluble diluents can besalts or saccharides that can dissolve quickly in water. Examplesinclude but not limited to sodium dihydrogen phosphate, sodium,potassium, magnesium and zinc sulfates, sodium and potassium chlorides,sorbitol, sodium benzoate, lactose, and sucrose. Insoluble diluentsinclude but not limited to clay, synthetic and diatomaceous silicas,calcium and magnesium silicates, titanium, aluminium, calcium and zincoxides, calcium and magnesium carbonates, sodium sulfate, potassiumsulfate, calcium and barium sulfates, and charcoal. Preferred aresoluble diluents.

Apart from dicamba, at least one sulfonamide free acid activeingredient, at least one solid base, and optionally diluents, theagrochemical composition may also include stabilizers, adjuvant andcoloring agents as appropriate.

The agrochemical composition of embodiments of the present invention canbe in the form of wettable powder and water-soluble powder, etc, butmore preferably in the form of water-soluble granule. Similarly, the dryformulations of the present invention can be in the form of aggregate,matrix or integrity, like block, granule, tablet, stick, film, and thinslice, etc. The dry formulations of the present invention are preferablyto be embedded in soluble matrix or integrity. One skilled in the arthas also realized that the present invention shall further includepacking the fast-soluble dry formulations into soluble packages such asbags, pouches, sachets and capsules etc.

In addition, an embodiment of the present invention relates to a methodof preparing a water-soluble granule (SG) comprising dicamba or itssalt, at least one sulfonamide free acid active ingredient and at leastone solid base for controlling field weeds. The method comprises thefollowing steps:

-   -   (1) Preparing a mixture in powder form, which comprises dicamba,        at least one sulfonamide free acid active ingredient, and at        least one solid base;    -   (2) Adding water to the mixture;    -   (3) Extruding the wet mixture through a die to obtain granules;    -   (4) Drying the granules.

The present invention also provides an embodiment relating toadministration method of a water-soluble granule, comprising:

-   -   (1) Preparing a water-soluble granule comprising a mixture of        dicamba or its salt, at least one sulfonamide free acid active        ingredient and at least one solid base;    -   (2) Mixing the water-soluble granule with water to obtain a        clear diluted solution;    -   (3) Applying the agrochemical/water mixture.

The present invention also involves an embodiment relating to thepreparation of an agrochemical/water mixture by using the said method.

The said dry formulations can be applied with the methods well known inthe art. These methods include coating, spraying, dip, soaking,injection, and irrigation, etc.

The agrochemical composition of embodiments of the present invention isusually applied after dilution with water. One skilled in the art shallfind that, while diluting by water, the dilution factor of theagrochemical composition varies according to types of agrochemicalcomposition, types of harmful organisms to be controlled, types of cropsto be treated, types of bacteria to be reduced, types of weeds to becontrolled, duration of treatment and methods of application etc.However, the range is usually within 20 to 10,000 times.

In the present invention, unless otherwise specified, all percentages(expressing ratio or content) are by weight.

EXAMPLES Example 1 40% Dicamba+6% Nicosulfuron SG (Water-SolubleGranule)

Dicamba 40%  Nicosulfuron 6% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Sodium carbonate (Na₂CO₃) 1% Potassium sulfate (K₂SO₄) 47.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulations is obtainedafter drying of the granules.

Comparative Example A 40% Dicamba+6% Nicosulfuron SG

Dicamba 40%  Nicosulfuron 6% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Potassium sulfate (K₂SO₄) 48.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulations is obtainedafter drying of the granules.

Example 2 1% Dicamba+1% Nicosulfuron SP (Water-Soluble Powder)

Dicamba 1% Nicosulfuron 1% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)2.5%  Sodium carbonate (Na₂CO₃) 1% Sodium acetate (NaOAc) 89% 

The active ingredients are thoroughly mixed with the adjuvant, andmilled in a suitable mill to form the water-soluble powder.

Comparative Example B 1% Dicamba+1% Nicosulfuron SP

Dicamba  1% Nicosulfuron  1% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5% Reax ® 88B (sodium lignosulfonate, Westvaco Corp)2.5% Sucrose  90%

The active ingredients are thoroughly mixed with the adjuvant, andmilled in a suitable mill to form the water-soluble powder.

Example 3 3.5% Dicamba+90% Nicosulfuron SP

Dicamba 3.5% Nicosulfuron  90% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5% Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Sodium carbonate (Na₂CO₃)  1%

The active ingredients are thoroughly mixed with the adjuvant, andmilled in a suitable mill to form the water-soluble powder.

Comparative Example C 3.5% Dicamba+90% Nicosulfuron SP

Dicamba 3.5% Nicosulfuron  90% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5% Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Sucrose  1%

The active ingredients are thoroughly mixed with the adjuvant, andmilled in a suitable mill to form the water-soluble powder.

Example 4 9% Dicamba+15% Nicosulfuron SG

Dicamba  9% Nicosulfuron 15% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Sodium carbonate monohydrate (Na₂CO₃•H₂O) 20% Lactose 50.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulations is obtainedafter drying of the granules.

Comparative Example D 9% Dicamba+15% Nicosulfuron SG

Dicamba 9% Nicosulfuron 15%  Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Lactose 70.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulations is obtainedafter drying of the granules.

Example 5 60% Dicamba+15% Nicosulfuron SP

Dicamba 60% Nicosulfuron 15% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Sodium phosphate (Na₃PO₄) 19.5% 

The active ingredients are thoroughly mixed with the adjuvant, andmilled in a suitable mill to form the water-soluble powder.

Comparative Example E 60% Dicamba+15% Nicosulfuron SP

Dicamba 60% Nicosulfuron 15% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Lactose 19.5% 

The active ingredients are thoroughly mixed with the adjuvant, andmilled in a suitable mill to form the water-soluble powder.

Example 6 30% Dicamba+10% Pyrazosulfuron SG

Dicamba 30% Pyrazosulfuron 10% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Potassium carbonate (K₂CO₃) 10% Lactose 44.5% 

The abovementioned substances are well mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example F 30% Dicamba+10% Pyrazosulfuron SG

Dicamba 30% Pyrazosulfuron 10% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Lactose 54.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 7 48% Dicamba+2% Tribenuron SG

Dicamba 48% Tribenuron  2% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Potassium hydrogen carbonate (KHCO₃) 40% Sucrose 4.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example G 48% Dicamba+2% Tribenuron SG

Dicamba 48%  Tribenuron 2% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Sucrose 44.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 8 4% Dicamba+40% Ethametsulfuron SG

Dicamba 4% Ethametsulfuron 40%  Supralate ® (sodium lauryl sulfate,Witco Inc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, WestvacoCorp) 5% Sodium hydrogen carbonate (NaHCO₃) 2% Lactose 48.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example H 4% Dicamba+40% Ethametsulfuron SG

Dicamba 4% Ethametsulfuron 40%  Supralate ® (sodium lauryl sulfate,Witco Inc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, WestvacoCorp) 5% Lactose 50.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 9 49% Dicamba+1% Florasulam SG

Dicamba 49% Florasulam  1% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Disodium hydrogen phosphate (Na₂HPO₄) 10% Lactose 34.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example I 49% Dicamba+1% Florasulam SG

Dicamba 49%  Florasulam 1% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Lactose 44.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 10 5% Dicamba+50% Diclosulam SG

Dicamba 5% Diclosulam 50%  Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Potassium hydroxide 1% Lactose 38.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example J 5% Dicamba+50% Diclosulam SG

Dicamba 5% Diclosulam 50%  Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Lactose 39.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 11 18% Dicamba+1% Metsulfuron SG

Dicamba 18% Metsulfuron  1% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Potassium hydrogen carbonate (KHCO₃) 50% Lactose 25.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example K 18% Dicamba+1% Metsulfuron SG

Dicamba 18%  Metsulfuron 1% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)5% Lactose 75.5%  

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 12 10% Dicamba+50% Bensulfuron SG

Dicamba 10% Bensulfuron 50% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Potassium phosphate (K₃PO₄)  1% Sucrose 33.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example L 10% Dicamba+50% Bensulfuron SG

Dicamba 10% Bensulfuron 50% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Sucrose 34.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 13 60% Dicamba+10% Penoxsulam SG

Dicamba 60% Penoxsulam 10% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Dipotassium hydrogen phosphate (K₂HPO₄)  1% Sucrose 23.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example M 60% Dicamba+10% Penoxsulam SG

Dicamba 60% Penoxsulam 10% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp) 5% Sucrose 24.5% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 14 40% Dicamba+5% Rimsulfuron SG

Dicamba 40% Rimsulfuron  5% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sodium phosphate dodecahydrate (Na₃PO₄•12H₂O) 50%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example N 40% Dicamba+5% Rimsulfuron SG

Dicamba 40% Rimsulfuron  5% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Lactose 50%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 15 60% Dicamba+5% Sulfometuron SG

Dicamba 60% Sulfometuron  5% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Potassium pyrophosphate (K₄P₂O₇)  1% Lactose 29%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example O 60% Dicamba+5% Sulfometuron SG

Dicamba 60% Sulfometuron  5% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Lactose 30%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 16 40% Dicamba+5% Thifensulfuon SG

Dicamba 40% Thifensulfuon  5% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Diammonium hydrogen phosphate ((NH₄)₂HPO₄) 25% Lactose 25%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example P 40% Dicamba+5% Thifensulfuon SG

Dicamba  40% Thifensulfuon   5% Supralate ® (sodium lauryl sulfate,Witco Inc., Greenwich) 0.5% Reax ® 88B (sodium lignosulfonate, WestvacoCorp) 4.5% Lactose  50%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 17 20% Dicamba+10% Mesosulfuron SG

Dicamba 20% Mesosulfuron 10% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sodium silicate (Na₂SiO₃) 10% Sucrose 55%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example Q 20% Dicamba+10% Mesosulfuron SG

Dicamba 20% Mesosulfuron 10% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sucrose 65%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 18 29.2% Dicamba+1.5% Amidosulfuron SG

Dicamba 29.2%  Amidosulfuron 1.5% Supralate ® (sodium lauryl sulfate,Witco Inc., Greenwich) 0.5% Reax ® 88B (sodium lignosulfonate, WestvacoCorp) 4.5% Sodium tripolyphosphate (Na₅P₃O₁₀)  3% Lactose 61.3% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example R 29.2% Dicamba+1.5% Amidosulfuron SG

Dicamba 29.2%  Amidosulfuron 1.5% Supralate ® (sodium lauryl sulfate,Witco Inc., Greenwich) 0.5% Reax ® 88B (sodium lignosulfonate, WestvacoCorp) 4.5% Lactose 64.3% 

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 19 40% Dicamba+20% Azimsulfuron SG

Dicamba 40% Azimsulfuron 20% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sodium trisilicate (Na₂Si₃O₇)  5% Sucrose 30%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example S 40% Dicamba+20% Azimsulfuron SG

Dicamba 40% Azimsulfuron 20% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sucrose 35%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 20 30% Dicamba+30% Chlorimuron SG

Dicamba 30% Chlorimuron 30% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sodium polyphosphate ((NaPO₃)_(n)) 20% Lactose 15%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example T 30% Dicamba+30% Chlorimuron SG

Dicamba 30% Chlorimuron 30% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Lactose 35%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 21 20% Dicamba+60% Tritosulfuron SG

Dicamba 20% Tritosulfuron 60% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sodium hexametaphosphate ((NaPO₃)₆) 15%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example U 20% Dicamba+60% Tritosulfuron SG

Dicamba 20% Tritosulfuron 60% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Lactose 15%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Example 22 10% Dicamba+70% Chlorsulfuron SG

Dicamba 10% Chlorsulfuron 70% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sodium silicate ((Na₂SiO₃)₆) 15%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Comparative Example V 10% Dicamba+70% Chlorsulfuron SG

Dicamba 10% Chlorsulfuron 70% Supralate ® (sodium lauryl sulfate, WitcoInc., Greenwich) 0.5%  Reax ® 88B (sodium lignosulfonate, Westvaco Corp)4.5%  Sucrose 15%

The abovementioned substances are well-mixed and milled with suitableamount of water to form granules, and the said formulation is obtainedafter drying of the granules.

Laboratory Cleanout Test Procedure

The test is conducted on the diluted solutions obtained by dispersingthe samples of Examples 1 to 22 and Comparative examples A to V inwater. 1 g of the samples is added to tap water (300 mL) in a 400-mLbeaker for magnetic stirring for 2 minutes. The resulting dilutedsolution is dispensed in three 100 mL aliquots to 4-oz (118-mL)polyethylene bottles. The bottles are capped, inverted twice and allowedto stand overnight. After standing overnight, each individual bottle isinverted twice and the liquid contents are then poured out. Tap water(10 mL) is added and the bottle is inverted until all sediments arere-suspended, whereupon the contents are poured out. Tap water (10 mL)is added and the bottle is inverted twice and then allowed to standundisturbed for 10 minutes. The bottle is inverted twice more and thecontents are poured out. Acetonitrile (10 mL) is added to the bottle toextract any remaining material. The acetonitrile solution is analyzed bya reversed-phase liquid chromatography with UV detector. The cleanoutrate (the concentration of sulfonamide in acetonitrile solution) isreported in ppm in the following table. Lower cleanout ratings indicatemore efficient cleanout when compared to higher ratings.

Cleanout Amount of rating Sulfonamide sulfonamide Base Sulfonamide: (ppmEx. ingredient (%) Base ingredient (%) Base sulfonamide) 1 Nicosulfuron 6% Sodium carbonate  1% 6:1 0 2 Nicosulfuron  1% Sodium carbonate 90% 1:90 0 Sodium acetate 3 Nicosulfuron 90% Sodium carbonate  1% 90:1  504 Nicosulfuron 15% Sodium carbonate 20% 3:4 2 monohyrdrate 5Nicosulfuron 15% Sodium phosphate 19.5%     1:1.3 4 6 Pyrazosulfuron 10%Potassium 10% 1:1 10 carbonate 7 Tribenuron  2% Potassium 40%  1:20 5hydrogen carbonate 8 Ethametsulfuron 40% Sodium hydrogen  2% 20:1  6carbonate 9 Florasulam  1% Disodium hydrogen 10%  1:10 15 phosphate 10Diclosulam 50% Potassium  1% 50:1  5 hydroxide 11 Metsulfuron  1%Potassium 50%  1:50 3 hydrogen carbonate 12 Bensulfuron 50% Potassium 1% 50:1  25 phosphate 13 Penoxsulam 10% Dipotassium  1% 10:1  20hydrogen phosphate 14 Rimsulfuron  5% Sodium phosphate 50%  1:10 0dodecahydrate 15 Sulfometuron  5% Potassium  1% 5:1 9 pyrophosphate 16Thifensulfuon  5% Diammonium 25% 1:5 5 hydrogen phosphate 17Mesosulfuron 10% Sodium silicate 10% 1:1 7 18 Amidosulfuron 1.5%  Sodium 3% 1:2 1 tripolyphosphate 19 Azimsulfuron 20% Sodium trisilicate  5%4:1 60 20 Chlorimuron 30% Sodium 20% 3:2 46 polyphoshate 21Tritosulfuron 60% Sodium 15% 4:1 30 hexametaphosphate 22 Chlorsulfuron70% Sodium silicate 15% 4.7:1   25 A Nicosulfuron  6% nil nil nil 1000 BNicosulfuron  1% nil nil nil 400 C Nicosulfuron 90% nil nil nil 890,123D Nicosulfuron 15% nil nil nil 34,213 E Nicosulfuron 15% nil nil nil53,254 F Pyrazosulfuron 10% nil nil nil 28,900 G Tribenuron  2% nil nilnil 800 H Ethametsulfuron 40% nil nil nil 320,180 I Tribenuron  1% nilnil nil 500 J Tribenuron 50% nil nil nil 432,980 K Metsulfuron  1% nilnil nil 300 L Bensulfuron 50% nil nil nil 443,650 M Penoxsulam 10% nilnil nil 27,800 N Rimsulfuron  5% nil nil nil 590 O Sulfometuron  5% nilnil nil 850 P Thifensulfuon  5% nil nil nil 740 Q Mesosulfuron 10% nilnil nil 38,800 R Amidosulfuron 1.5%  nil nil nil 870 S Azimsulfuron 20%nil nil nil 119,860 T Chlorimuron 30% nil nil nil 250,000 UTritosulfuron 60% nil nil nil 430,245 V Chlorsulfuron 70% nil nil nil532,134

The cleanout rating data in the above table shows that adding a solidbase into the herbicidal composition according to the present inventioncomprising dicamba and a sulfonamide free acid can significantly reducethe amount of sulfonamide residues in the bottle.

Bioassay Protocol:

The test is conducted on the diluted solutions obtained by dispersing 1g of the samples of Examples 1 to 22 and Comparative examples A to V inwater. The resulting diluted solution is dispensed in three 100-mLaliquots to 4-oz (118-mL) polyethylene bottles. The bottles are capped,inverted twice and allowed to stand overnight. After standing overnight,each individual bottle is inverted twice and the liquid contents arethen poured out. Tap water (10 mL) is added and the bottle is inverteduntil all sediments are re-suspended, whereupon the contents are pouredout. Tap water (10 mL) is added and the bottle is inverted twice andthen allowed to stand undisturbed for 10 minutes. The bottle is invertedtwice more and the contents are poured out. In the above cleanoutprocedure, acetonitrile (10 mL) is added to the bottle to extract anyremaining material. The acetonitrile solution is analyzed by areversed-phase liquid chromatography with UV detector. In this bioassayprocedure, 1000 mL fresh water is added to the bottle. The final rinsesolution is sprayed on the crops (sugar beet). The bioassay protocolemployed shall determine the percent injury of the crop. Sugar beetseedlings (at the two-leaf stage) are grown in greenhouse (14 hours at21° C. with light and 10 hours at 17° C. in the dark) and sprayed withthe above final rinse solution. Three replicates, with four sugar beetplants/pot, are treated with each sample.

Plants are held in the greenhouse until they are evaluated 14 to 23 daysafter treatment. Injury of treated plants is assessed visually on ascale of 0 to 100 (0=no injury, 100=completely killed) compared tocontrol plants. Injury ratings are based on the presence of varioussymptoms, including reduced biomass, stunting, inhibited development,chlorosis, necrosis, leaf spotting, and leaf puckering or deformation.

Comparative Example Injury level example Injury level 1 0 A 20 2 0 B 203 5 C 100 4 0 D 60 5 0 E 60 6 0 F 60 7 0 G 30 8 0 H 100 9 0 I 20 10 0 J100 11 0 K 10 12 0 L 100 13 0 M 50 14 0 N 20 15 0 O 30 16 0 P 20 17 0 Q70 18 0 R 30 19 5 S 100 20 5 T 100 21 5 U 100 22 5 V 100

The data in the above table shows that adding a solid base into theherbicidal composition according to the Examples 1 to 22 of the presentinvention comprising dicamba and a sulfonamide free acid cansignificantly reduce the sulfonamide residues in the spray tank. Thereis almost no injury shown on the sugar beet sprayed with the final rinsesolution. The Comparative examples A to V show serious injuries on thesugar beet sprayed with the final rinse solution if the sulfonamidepresents in an amount of more than 10% of the composition comprisingdicamba and sulfonamide.

The invention claimed is:
 1. An agrochemical composition comprising:dicamba or its salt, a sulfonamide herbicide free acid, a solid base andoptionally an agriculturally acceptable carrier; wherein the sulfonamideherbicide free acid is nicosulfuron; wherein the weight ratio of thesolid base to nicosulfuron is from 1:90 to 90:1; wherein the solid baseis present in an amount of at least 1% of the total weight of theagrochemical composition; and wherein the presence of the solid basereduces the presence of nicosulfuron residue in an application tank andimproves clean-out of nicosulfuron in the application tank relative tothe agrochemical composition that does not include the solid base. 2.The agrochemical composition according to claim 1, wherein theagrochemical composition is in solid form.
 3. The agrochemicalcomposition according to claim 1, wherein the solid base is selectedfrom one or more of the group consisting of sodium hydrogen carbonate,sodium carbonate, disodium hydrogen phosphate, sodium phosphate,potassium carbonate, dipotassium hydrogen phosphate, potassiumphosphate, potassium hydrogen carbonate, potassium hydroxide, sodiumcarbonate hydrate, sodium acetate, sodium tripolyphosphate, sodiumphosphate dodecahydrate, diammonium hydrogen phosphate, sodium silicate,sodium trisilicate, sodium polyphosphate, sodium hexametaphosphate andpotassium pyrophosphate.
 4. The agrochemical composition according toclaim 3, wherein the solid base is selected from one or more of thegroup consisting of sodium acetate, sodium carbonate, disodium hydrogenphosphate, sodium phosphate, potassium hydrogen carbonate, potassiumcarbonate, dipotassium hydrogen phosphate and potassium phosphate.
 5. Amethod of controlling field weeds, the method comprising applying to thefield weeds the agrochemical composition according to claim
 1. 6. Amethod according to claim 5 which further comprises applying theagrochemical composition with an application tank.
 7. The agrochemicalcomposition according to claim 2, wherein the agrochemical compositionis in the form of wettable powder, water soluble powder or water solublegranule.
 8. The agrochemical composition according to claim 7, whereinthe agrochemical composition is in a form of a water soluble granule. 9.The agrochemical composition according to claim 4, wherein the solidbase is selected from the group consisting of sodium carbonate, sodiumphosphate, potassium carbonate and potassium phosphate.
 10. Theagrochemical composition according to claim 9, wherein the solid base issodium carbonate.
 11. The method according to claim 6, wherein theapplication tank is a spray tank.
 12. A method of preparing anagrochemical composition, comprising the mixing of a solid base withdicamba or its salt and a nicosulfuron to establish a weight ratio ofthe solid base to nicosulfuron from 1:90 to 90:1 and the presence of thesolid base in an amount of at least 1% of the total weight of theagrochemical composition, wherein the presence of the solid base reducesthe presence of nicosulfuron residue in the application tank andimproves clean-out of the nicosulfuron in the application tank relativeto the agrochemical composition that is not prepared with the solidbase.